arXiv subjects

A. Senol

Publications and source records attributed to A. Senol.

At least 37 records · Page 2Linked to original sources

arXiv2019

Testing for observability of Higgs effective couplings in triphoton production at FCC-hh

We investigate the potential of the $pp\to γγγ$ process to probe CP-conserving and CP-violating dimension-six operators of Higgs-gauge boson interactions in a model-independent Standard Model effective field theory framework at the center of mass energy of 100 TeV which is designed for the Future Circular hadron-hadron Collider. Signal events assuming the existence of anomalous Higgs boson couplings at $Hγγ$ and $HZγ$ vertices and the relevant SM background events are generated in MadGraph, then passed through Pythia 8 for parton showering and Delphes to include detector effects. After detailed examination of kinematic variables, we use the invariant mass distribution of the two leading photons with optimized kinematic cuts to obtain constraints on the Wilson coefficients of dimension-six operators. We report that limits at 95\% confidence level on $\bar{c}_γ$ and $\tilde{c}_γ$ couplings with an integrated luminosity of 10 ab$^{-1}$ are [-0.0051; 0.0038] and [-0.0043; 0.0043] without systematic error, respectively.

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arXiv2019

Top quark anomalous FCNC production via $tqg$ couplings at FCC-hh

We investigate the top quark anomalous Flavor Changing Neutral Current (FCNC) $tqg$ interactions to probe limits on the couplings $ζ_c$ and $ζ_u$ through the $qg \to lνb$ signal suprocess at FCC-hh collider with center of mass energy of 100 TeV. To separate signal from relevant Standard Model background processes, selection criteria based on Boosted Decision Trees (BDT) is used with a set of useful kinematic variables. The sensitivities on the anomalous top FCNC couplings $ζ_u$ and $ζ_c$ are found to be $1.239\times10^{-4}$ and $1.149\times10^{-4}$ for FCC-hh with $L_{int}$=10 ab$^{-1}$ at 95 \% C.L. including realistic detector effects of the FCC-hh baseline detector, respectively. The branchings $BR (t \to ug)$ and $BR (t \to c g)$ converted from obtained limits for FCNC couplings are at the order of $10^{-7}$ which is at least one order of magnitude better than the projected limits of HL-LHC with $L_{int}$= 3 ab$^{-1}$.

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arXiv2019

Study on Anomalous Neutral Triple Gauge Boson Couplings from Dimension-eight Operators at the HL-LHC

The anomalous neutral triple gauge boson couplings (aNTGCs) for the Z gamma gamma and Z gamma Z vertices described by dimension-eight operators are examined through the process pp to l^{+}l^{-} gamma at the High-Luminosity Large Hadron Collider (HL-LHC). We performed an analysis on transverse momentum of photon and angular distribution of charged lepton in the final state including detector effects. Sensitivity limits of the C_{\widetilde{B}W}, C_{BB} couplings are obtained at 95 % C.L. to constrain for the range [-1.88: 1.88] TeV^{-4}, [-1.47: 1.47] TeV^{-4} and [-1.14:1.14] TeV^{-4}, [-0.86: 0.86] TeV^{-4} with an integrated luminosity of 300 fb^{-1} and 3000 fb^{-1}, respectively.

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arXiv2019

Sensitivity on Anomalous Neutral Triple Gauge Couplings via $ZZ$ Production at FCC-hh

We study the sensitivity of anomalous neutral triple gauge couplings ($aNTGC$) via $pp \rightarrow ZZ$ production in the 4$\ell$ channel at 100 TeV centre of mass energy of future circular hadron collider, \verb"FCC-hh". The analysis including the realistic detector effects is performed in the mode where both Z bosons decay into same flavor, oppositely charged lepton pairs. The sensitivities to the charge-parity (CP)-conserving $C_{\tilde{B}W} / Λ^{4}$ and CP-violating $C_{WW} / Λ^{4}$, $C_{BW} / Λ^{4}$ and $C_{BB} / Λ^{4}$ couplings obtained at 95\% Confidence Level (C.L.) using the invariant mass distribution of 4$\ell$ system reconstructing the leading and sub-leading Z boson candidates are $[-0.117, \,\, +0.117]$, $[-0.293, \,\, +0.292]$, $[-0.380, \,\, +0.379]$, and $[-0.138, \,\, +0.138]$ in the unit of TeV$^{-4}$, respectively.

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arXiv2019

Probing Top Quark FCNC tqgamma and tqZ Couplings at Future Electron-Proton Colliders

The top quark flavor changing neutral current (FCNC) processes are extremely suppressed within the Standard Model (SM) of particle physics. However, they could be enhanced in a new physics model Beyond the Standard Model (BSM). The top quark FCNC interactions would be a good test of new physics at present and future colliders. Within the framework of the BSM models, these interactions can be described by an effective Lagrangian. In this work, we study tqgamma and tqZ effective FCNC interaction vertices through the process e-p->e-Wq+X at future electron proton colliders, projected as Large Hadron electron Collider (LHeC) and Future Circular Collider-hadron electron (FCC-he). The cross sections for the signal have been calculated for different values of parameters lambda_q for tqgamma vertices and kappa_q for $tqZ$ vertices. Taking into account the relevant background we estimate the attainable range of signal parameters as a function of the integrated luminosity and present contour plots of couplings for different significance levels including detector simulation.

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arXiv2019

Probing anomalous $tqγ$ and $tqg$ couplings via single top production in association with photon at FCC-hh

We study the anomalous FCNC $tqγ$ and $tqg$ couplings via $pp\to Wbγ+X$ signal process including realistic detector effects for both leptonic and hadronic decay channels of the W boson at 100 TeV FCC-hh. The relevant background are considered in the cut based analysis to obtain not only limits on the anomalous $λ$ and $ζ$ couplings but also branching ratios of $t\to qγ$ and $t\to qg$ decay channels. We find that the sensitivity to the branching ratio of $t \to q γ$ channel is three order better than the available LHC experimental limits, and it is comparable for the branching ratio of the $t\to qg$ decay channel with an integrated luminosity of 10 ab$^{-1}$ at 2$σ$ significance level.

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arXiv2018

Probing the Effects of Dimension-eight Operators Describing Anomalous Neutral Triple Gauge Boson Interactions at FCC-hh

The effects of dimension-eight operators giving rise to anomalous neutral triple gauge boson interactions of $Zγγ$ and $ZγZ$ vertices in $pp\to l^-l^+γ$ and $pp\to ν\bar νγ$ are investigated at 100 TeV centre of mass energy of future circular hadron collider (FCC-hh). The transverse momentum of photon, invariant mass of $l^-l^+γ$ and angular distribution of charged lepton in the rest frame of $l^-l^+$ and Missing Energy Transverse (MET) are considered in the analysis. The realistic detector effects are also included with Delphes simulation. Sensitivity limits obtained at 95\% C.L. for $C_{\widetilde B W}/Λ^4$ and $C_{B B}/Λ^4$ couplings are $[-0.52;0.52] ([-0.40;0.40])$ TeV$^{-4}$, $[-0.43;0.43] ([-0.33;0.33])$ TeV$^{-4}$ in the dilepton+photon channel and $[-0.11;0.11] ([-0.084;0.084])$ TeV$^{-4}$, $[-0.092;0.092] ([-0.072;0.072])$ TeV$^{-4}$ in the MET+photon channel with $L_{int}$=1 (3) ab$^{-1}$, respectively.

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arXiv2018

Constraints on Higgs effective couplings in $Hν\barν$ production of CLIC at 380 GeV

The potential of the $e^+e^-\toν\barν H$ process in the first stage of CLIC considering center of mass energy of 380 GeV and assuming the baseline integrated luminosity of 500 fb$^{-1}$ is examined to probe CP conserving dimension-six operators in a model-independent Standard Model effective field theory framework. In the analysis, a detailed fast simulation on $e^+e^-\toν\barν H$ signal processes and dominant backgrounds are performed including parton showering with PYTHIA and detector simulation based on ILD type detector with DELPHES in MadGraph. The obtained best limits on the $\bar{c}_{HB} $, $\bar{c}_{W}=- \bar{c}_{B}$ and $\bar{c}_{HW} $ are $[-4.82;1.53]\times10^{-2}$, $[-5.11;4.13]\times10^{-3}$ and $[-6.58;5.55]\times10^{-3}$, respectively.

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arXiv2017

Probing the Anomalous FCNC tqgamma Couplings at Large Hadron electron Collider

We investigate the anomalous flavour changing neutral current (FCNC) interactions of top quark through the process $e^{-}p\to e^{-}W^{\pm}q+X$. We calculate the signal and background cross sections in electron proton collisions at Large Hadron electron Collider (LHeC) with a 7 TeV proton beam from the LHC and a new 60 GeV electron beam from energy recovery linac (ERL). We study the relevant background processes including one electron and three jets in the final state. The distributions of the invariant mass of two jets and an additional jet tagged as $b$-jet are used to account signal and background events after the analysis cuts. We find upper bounds on anomalous FCNC couplings $λ$ of the order of $10^{-2}$ at LHeC for a luminosity projection of $100$ fb$^{-1}$ together with the fast simulation of detector effects. As a matter of interest, we analyze the sensitivity to the couplings $(λ_{u},λ_{c})$ and find an enhanced sensitivity to $λ_{c}$ at the LHeC when compared to the results from the HERA.

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arXiv2017

Top quark FCNC couplings at future circular hadron electron colliders

A study of single top quark production via flavor changing neutral current interactions at $tqγ$ vertices is performed at future circular hadron electron collider. The signal cross sections for the processes $e^{-}p\to e^{-}W^{\pm}q+X$ and $e^{-}p\to e^{-}W^{\pm}bq+X$ in the collision of electron beam with energy $E_e=$ 60 GeV and proton beam with energy $E_p=$ 50 TeV are calculated. In the analysis, the invariant mass distributions of three jets reconstructing top quark mass, requiring one b-tagged jet and other two jets reconstructing the $W$ mass are used to count signal and background events after all selection cuts. The upper limits on the anomalous flavor changing neutral current $tqγ$ couplings are found to be $λ_q < $ 0.01 at future circular hadron electron collider for $L_{int}=100$ fb$^{-1}$ with the fast simulation of detector effects. Signal significance depending on the couplings $λ_q$ is analyzed and an enhanced sensitivity is found to the branching ratio BR($t\to qγ$) at the future circular hadron electron collider when compared to the current experimental results.

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arXiv2017

Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of the $e^{+}e^{-}\rightarrow ν_{e} W^{-} W^{+} \barν_{e}$ process for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the $95\%$ confidence level bounds on anomalous $\frac{f_{S0}}{Λ^{4}}$, $\frac{f_{S1}}{Λ^{4}}$ and $\frac{f_{T0}}{Λ^{4}}$ couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalous $\frac{f_{S0}}{Λ^{4}}$, $\frac{f_{S1}}{Λ^{4}}$ and $\frac{f_{T0}}{Λ^{4}}$ couplings through the process $e^{+}e^{-}\rightarrow ν_{e} W^{-} W^{+} \barν_{e}$ with beam polarization at $\sqrt{s}=3$ TeV and an integrated luminosity of $L_{int}=2000$ fb$^{-1}$ are $[-4.05;\, 3.67]\times 10^{-12}$ GeV$^{-4}$, $[-3.08; \, 2.12]\times 10^{-12}$ GeV$^{-4}$, $[-1.98; \, 0.64]\times 10^{-13}$ GeV$^{-4}$, which show improvement over the current bounds.

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arXiv2016

Search for anomalous quartic $ZZγγ$ couplings in photon-photon collisions

The self-couplings of the electroweak gauge bosons are completely specified by the non-Abelian gauge nature of the Standard Model (SM). The direct study of these couplings provides a significant opportunity to test the validity of the SM and the existence of new physics beyond the SM up to the high energy scale. For this reason, we investigate the potential of the processes $γγ\rightarrow ZZ$, $e^{-}γ\rightarrow e^{-}γ^{*}γ\rightarrow e^{-}Z\, Z$ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+}\, Z\, Z\, e^{-}$ to examine the anomalous quartic couplings of $ZZγγ$ vertex at the Compact Linear Collider (CLIC) with center-of-mass energy $3$ TeV. We calculate $95\%$ confidence level sensitivities on the dimension-8 parameters with various values of the integrated luminosity. We show that the best bounds on the anomalous $\frac{f_{M2}}{Λ^{4}}$, $\frac{f_{M3}}{Λ^{4}}$, $\frac{f_{T0}}{Λ^4}$ and $\frac{f_{T9}}{Λ^4}$ couplings arise from $γγ\rightarrow ZZ$ process among those three processes at center-of-mass energy of 3 TeV and integrated luminosity of $L_{int}=2000$ fb$^{-1}$ are found to be $[-3.30;3.30]\times 10 ^{-3}$ TeV$^{-4}$, $[-1.20;1.20]\times 10 ^{-2}$ TeV$^{-4}$, $[-3.40;3.40]\times 10 ^{-3}$ TeV$^{-4}$ and $[-1.80;1.80]\times 10 ^{-3}$ TeV$^{-4}$, respectively.

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arXiv2015

Search for anomalous quartic $WWZγ$ couplings at the future linear $e^{+}e^{-}$ collider

In this paper, the potentials of two different processes $e^{+}e^{-}\rightarrow W^{-} W^{+}γ$ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} e^{-} \rightarrow e^{+} W^{-} Z ν_{e}$ at the Compact Linear Collider (CLIC) are examined to probe the anomalous quartic $WWZγ$ gauge couplings. For $\sqrt{s}=0.5, 1.5$ and 3 TeV energies at the CLIC, $95\%$ confidence level limits on the anomalous coupling parameters defining the dimension-six operators are found via the effective Lagrangian approach in a model independent way. The best limits on the anomalous couplings $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ which can be achieved with the integrated luminosity of $L_{int}=590$ fb$^{-1}$ at the CLIC with $\sqrt{s}=3$ TeV are $[-8.80;\, 8.73]\times 10^{-8}$ GeV$^{-2}$, $[-1.53; \, 1.51]\times 10^{-7}$ GeV$^{-2}$, $[-3.75; \, 3.74]\times 10^{-7}$ GeV$^{-2}$ and $[-9.13;\,9.09]\times 10^{-7}$ GeV$^{-2}$, respectively.

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arXiv2015

Probing Charged Higgs Boson Couplings at the FCC-hh Collider

Many of the new physics models predicts a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at the FCC-hh collider. With an integrated luminosity of 500 fb$^{-1}$ at very high energy frontier, we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1 TeV.

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arXiv2015

Probe of anomalous quartic $WWZγ$ couplings in the photon-photon collisions

In this paper, we examine the potentials of the processes $γγ\rightarrow W^{+} W^{-}Z $ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ at the CLIC with $\sqrt{s}=0.5,1.5$ and $3$ TeV to investigate anomalous quartic $WWZγ$ couplings by two different CP-violating and CP-conserving effective Lagrangians. We find $95\%$ confidence level limits on the anomalous coupling parameters at the three CLIC energies and various integrated luminosities. The best limits obtained from the process $γγ\rightarrow W^{+} W^{-}Z $ on the anomalous $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$ and $\frac{k_{2}^{m}}{Λ^{2}}$ couplings defined by CP-conserving effective Lagrangians are $[-1.73;\, 1.73]\times 10^{-7}$ GeV$^{-2}$, $[-2.44;\, 2.44]\times 10^{-7}$ and $[-1.89; \, 1.89]\times 10^{-7}$ GeV$^{-2}$, while $\frac{a_{n}}{Λ^{2}}$ coupling determined by CP-violating effective Lagrangians is obtained as $[-1.74;\, 1.74]\times 10^{-7}$ GeV$^{-2}$. In addition, the best limits derived on $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$ and $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ from the process $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ are obtained as $[-1.09;\, 1.09]\times 10^{-6}$ GeV$^{-2}$, $[-1.54;\, 1.54]\times 10^{-6}$ GeV$^{-2}$, $[-1.18;\, 1.18]\times 10^{-6}$ and $[-1.04;\, 1.04]\times 10^{-6}$ GeV$^{-2}$, respectively.

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arXiv2015

Analysis of anomalous quartic $WWZγ$ couplings in $γp$ collision at the LHC

Gauge boson self-couplings are exactly determined by the non-Abelian gauge nature of the Standard Model (SM), thus precision measurements of these couplings at the LHC provide an important opportunity to test the gauge structure of the SM and the spontaneous symmetry breaking mechanism. It is a common way to examine the physics of anomalous quartic gauge boson couplings via effective Lagrangian method. In this work, we investigate the potential of the process $pp\rightarrow pγp\rightarrow p W Z q X$ to analyze anomalous quartic $WWZγ$ couplings by two different CP-violating and CP-conserving effective Lagrangians at the LHC. We calculate $95\%$ confidence level limits on the anomalous coupling parameters with various values of the integrated luminosity. Our numerical results show that the best limits obtained on the anomalous couplings $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ at $\sqrt{s}=14$ TeV and an integrated luminosity of $L_{int}=100$ fb$^{-1}$ are $[-1.37;\, 1.37]\times 10^{-6}$ GeV$^{-2}$, $[-1.88; \, 1.88]\times 10^{-6}$ GeV$^{-2}$, $[-6.55; \, 6.55]\times 10^{-7}$ GeV$^{-2}$ and $[-2.21;\,2.21]\times 10^{-6}$ GeV$^{-2}$, respectively. Thus, $γp$ mode of photon-induced reactions at the LHC highly improves the sensitivity limits of the anomalous coupling parameters $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$.

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arXiv2014

Anomalous quartic $WWγγ$ and $ZZγγ$ couplings in $γp$ collision at the LHC

We analyze the anomalous quartic gauge boson couplings $WWγγ$ and $ZZγγ$, described by dimension-6 effective quartic Lagrangian at the LHC. The sensitivities to anomalous quartic gauge couplings $a_{0,c}^{W,Z}/Λ^2$ by examining the two different photon-induced processes $pp\to pγp\to p WγqX$ and $pp\to pγp\to p ZZ qX$ with $W$ and $Z$s decaying leptonically are investigated. We show that $γp$ mode of photon-induced reactions at the LHC are able to probe these couplings to the order of $10^{-6}$-$10^{-7}$ GeV$^{-2}$ at 95 % confidence level with $\sqrt s$ = 14 TeV and for proton-proton luminosities in the range of 30-200 fb$^{-1}$.

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arXiv2014

Search for anomalous $WWγ$ and $WWZ$ couplings with polarized $e$-beam at the LHeC

We examine the potential of the $ep\toν_{e}qγX$ and $ep\toν_{e}qZX$ processes to search for the anomalous couplings of $WWγ$ and $WWZ$ vertices at the LHeC with the electron beam energy of $E_{e}=60$ GeV and $E_{e}=140$ GeV. The difference of maximum and minimum bounds on the anomalous couplings, ($δΔκ_γ$, $δλ_γ$) and ($δΔκ_{Z}$, $δλ_{Z}$) are obtained as ($0.990$, $0.122$) and ($0.362$, $0.012$) without electron beam polarization at the beam energy of $E_{e}=140$ GeV for an integrated luminosity of $L_{int}=100$ fb$^{-1}$, respectively. With the possibility of $e-$beam polarization, we obtain more improved results as ($0.975$, $0.118$) and ($0.285$, $0.009$) for ($δΔκ_γ, δλ_γ$) and ($δΔκ_{Z}, δλ_{Z}$), respectively. The results are found to be comparable with the current experimental limits obtained from two-parameter analysis at the lepton and hadron colliders. It is found that the limits on the anomalous couplings ($Δκ_{Z}$, $λ_{Z}$) through the process $ep\toν_{e}qZX$ at the LHeC can further improve the current experimental limits.

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